The present invention relates to a flat type connector means for splicing optical fibers to each other and, more particularly, to a flat type plastic connector means for enabling a simultaneous splicing of a plurality of optical fibers, and a method for assembing flat type connector means.
Optical fibers now have been replacing metal wire cables, since optical fibers are advantageously versatile, compact, lightweight, and free from any high-level electromagnetic interference. However, similarly to metal wire cables, an operation for splicing optical fibers to each other at a working site must be performed so that a splicing loss in a spliced portion will be sufficiently smaller than the total transmission loss in a fiber of a predetermined length.
In addition, it is required that the splicing portion on which optical fibers are connected to each other is easily formed, permanent, compact, lightweight and strong. In this case, above mentioned requirements except for the permanencey can be similarly applied to a connector for connecting a cable to a terminal device.
One widely employed splicing method includes a precision sleeve closely enclosing an outer periphery of a fiber to be connected, with the precision sleeve being used to guide and retain the fiber at a predetermined position. This method is most suitable for a single fiber or a cable having a small number of fibers, since it is necessary to individually handle the fibers.
With a large number of optical fibers, ,the fibers are retained and connected to each other between a metal or glass base having a plurality of grooves of a V-shaped cross-section formed on a surface thereof and a flat metal push plate. In this manner, an optical fiber constituted by a core and a cladding is retained in each groove by the flat push plate to form a connector. An axial end of the connector is to be ground. Optical fibers are connected to each other by abutting the ground ends of a pair of connectors to each other. In this case, the V-grooves are required to be machined with a strictly high accuracy in order to align the optical axes of optical fibers to be connected. Therefore, a considerable time is required for cutting such grooves and it is difficult to effect a mass production.
On the other hand, it has also been proposed to employ a silicon crystal base having a plurality of grooves of trapezoidal cross-section formed on a surface thereof by etching, instead of the cutting of a metal base. In this case, the dimensional accuracy of the cross-sectional configuration of the etched grooves is remarkably high, for example, .+-.1 .mu.m. However, such a base is exceedingly expensive and brittle. Moreover, it has been proposed to employ a base having a plurality of grooves of V-shaped cross-section formed by plastic injection molding using a mold produced by electroforming using a silicon base as a master. However, with this proposed method, considerable amounts of time and cost are required for production of a mold by electroforming, disadvantageously.
Accordingly, it is an object of the invention to provide a connector means for splicing optical fibers and method of assembling the same which is relatively inexpensive to manufacture and which avoids the above-mentioned disadvantages of the prior art.
It is another object of the invention to provide a connector means and assembly method by which optical fibers are connected to each other easily and highly accurately.
The above and other objects, features and advantages of the invention will become clear from the following description of the preferred embodiments made in connection with the accompanying drawings.